INVESTIGATION OF WASTEWATER IN QATAR USING MICROBIOLOGICAL AND CHEMICAL TECHNIQUES

Abstract

Qatar produces more than 800,000 m3/day of highly treated wastewater. However, a comprehensive wastewater reuse strategy is missing as only a limited part is being used for recreation and irrigation. Therefore, this thesis will investigate the wastewater in Qatar using microbiological and chemical techniques. It will also study the use of bacteriophages as a potential method for sustainable removal of pathogens in wastewater treatment. _x000D_ Samples of wastewater were collected from 11 stages of the wastewater treatment plant. Some physiochemical parameters were measured which showed that the wastewater in Qatar is neutral and fresh. Chemical parameters such as total organic carbon showed a steady decrease throughout the treatment stages. As for the anions, cations and heavy metals, the trends varied, however, all the measurements fell below national and international guidelines for irrigation use. As part of the microbiological analysis, the predominant phylum was established to be Proteobacteria which is also evident in the literature. Among other families consisting of pathogenic bacteria, Enterobacteriaceae family was found and this family was considered for bacteriophage isolation for understanding its potential in pathogen removal. Two phages were isolated using E.coli C as a host from the second wastewater treatment stage named Enterobacteria phage ADB-2 and Salmonella felixO1. However, only one phage; Salmonella felixO1 was isolated from the first stage. Salmonella felixO1 was considered as a candidate phage for host capture as they are polyvalent. Lysin and tail fiber proteins from this phage genome were established as essential for bacterial infection based on conserved domain studies. Finally, the DNA sequences of the candidate proteins were prepared for cloning by designing primers that amplify these regions of the phage genome. Further expression in a bacterial expression system shall enable the application of this phage as a biomonitoring tool in wastewater in Qatar.

Date of Award	2019
Original language	American English
Awarding Institution	HBKU College of Science and Engineering